Measurement of the Index of Refraction of a Flat Zinc Germanium Phosphide Wafer in the Infrared

We have developed and tested a novel application of interferometry to determine the absolute refractive index of individual infrared materials having flat and parallel surfaces without alteration of the sample in any way, and measured no for ZnGeP2

Content Validity of the Occupational Therapy Anticipatory Awareness Test: A Functional Cognitive Assessment for Adults with Neurological Conditions

Background: The development of assessments that measure functional skills is a priority in the profession. Anticipatory awareness (i.e., the ability to anticipate the difficulties that might be experienced in daily life situations) is a critical skill in occupational performance. There is a lack of assessments measuring anticipatory awareness. The Occupational Therapy Anticipatory Awareness Test (OTAAT) is a performance-based assessment tool developed for individuals with neurological conditions. This study aimed to determine the tool’s content validity. Methods: We recruited five experts to review whether the test items are essential for assessment and calculated the Content Validity Ratio (CVR). Open-ended questions allowed opportunity to provide feedback for tool revision. Results: Ten of the 14 items of the OTAAT were preserved. Eight out of the 14 items were rated as essential for measurement. Two of the 10 items were identified as useful but not essential. Following discussion, review of supporting literature, and analysis of qualitative feedback, the two emergent awareness items were kept. Four items were removed (strategy implementation and awareness of strategy use subdomains), as these were deemed not essential. Conclusion: This study determined preliminary content validity of the OTAAT. Future research should focus on establishing construct validity and test reliability

A Scoping Review of Self-Awareness Instruments for Acquired Brain Injury

Background: Self-awareness and insight are critical functions required to maintain safe and optimal participation in all daily life activities in a variety of environmental contexts. In the past two decades, occupational therapists have developed several psychometrically sound assessments designed to identify self-awareness and insight deficits in patients with neurological disorders. This scoping review identifies and evaluates key properties of such assessments to inform clinical practice. Method: Multiple electronic databases were searched using the key search terms of “self-awareness” and “self-awareness assessment,” and “insight” and “insight assessment.” Included studies were original primary sources from the peer-reviewed journals. Results: Nine assessments met the inclusion criteria: Assessment of Awareness of Disability, Awareness Interview, Awareness Questionnaire, Insight Interview, Patient Competency Rating Scale, Patient Competency Rating Scale for Neuro-Rehabilitation, Patient Distress Scale, Self-Awareness of Deficits Interview, and Self-Regulation Skills Interview. Each assessment is reviewed in detail regarding its purpose, administration time, format, type of awareness assessed, psychometric properties, and advantages and disadvantages. Conclusions: Although all nine assessments are psychometrically sound, some may hold more usefulness for occupational therapists depending on a variety of factors, including patient cognitive level and activity tolerance and clinical setting and time constraints

Application of Hertz Vector Diffraction Theory to the Diffraction of Focused Gaussian Beams and Calculations of Focal Parameters

Hertz vector diffraction theory is applied to a focused TEM00 Gaussian light field passing through a circular aperture. The resulting theoretical vector field model reproduces plane-wave diffractive behavior for severely clipped beams, expected Gaussian beam behavior for unperturbed focused Gaussian beams as well as unique diffracted-Gaussian behavior between the two regimes. The maximum intensity obtainable and the width of the beam in the focal plane are investigated as a function of the clipping ratio between the aperture radius and the beam width in the aperture plane

Use of Michelson and Fabry-Perot interferometry for independent determination of the refractive index and physical thickness of wafers

We present a method to independently measure the refractive index and the thickness of materials having flat and parallel sides by using a combination of Michelson and Fabry-Perot interferometry techniques. The method has been used to determine refractive-index values in the infrared with uncertainties in the third decimal place and thicknesses accurate to within Ϯ5 m for materials at room and cryogenic temperatures. © 2005 Optical Society of America OCIS codes: 120.2230, 120.3180, 120.4290, 160.4760. The refractive index, n, and the thermo-optic coefficient, dn͞dT, of materials are often determined by one's interferometrically measuring the phase change that light undergoes in passing through a plane-parallel slab of the material. Because the phase change depends on the value of n as well as the slab thickness, d, to obtain accurate values of n and dn͞dT, it is important to know d accurately. FabryPerot etalon interferometry has been used to optically measure d, 5 but the precision of thickness measurements with this method is limited by the precision of the known refractive-index value. Recent research by Coppala et al. 6 demonstrated that independent values for n and d can be obtained with interferometry and a continuously tunable laser source. In this paper we demonstrate that the Michelson and the Fabry-Perot interferometric methods can be used sequentially to determine independent and absolute values of both the material's thickness and the material's refractive index over a wide range of temperatures of practical interest. The method does not require that either quantity be initially well known. With this method, both n and d can be determined by use of a fixed-wavelength laser source. First, by use of data from both experiments, the material's physical thickness is determined. Then the thickness value is used to determine the material's refractive index (and thermo-optic coefficient) with either of the interferometric methods. We present experimental verification of this method by measuring n and d for a range of common infrared materials at both room temperature and cryogenic temperatures. The intensity of a coherent collimated beam of light transmitted by a plane-parallel transparent plate is given by the Airy formula 7 : where I o is the incident intensity, r is the reflection coefficient for the electric field, and f is the phase difference accumulated by the light beam in a double traversal through the plate. As the sample is rotated in the path of the laser light, the net transmitted intensity will modulate owing to the changing phase, f . The angle-dependent phase difference between subsequent transmitted light paths through the sample is given by 7 f () ϭ 4nd cos t ϭ 4d ͙n 2 Ϫ sin 2 , where d is the sample thickness, is the laser wavelength, t is the angle of refraction, and is the angle of incidence of the laser path with respect to the normal of the sample surface

Beyond Limits: A Stroke Survivor’s Journey to Preventing Arm Complication

Stroke is a major global health concern that often leads to upper limb weakness and significant recovery challenges due to secondary complications such as pain, swelling, and contractures. The purpose of this study is to introduce a comprehensive patient education manual designed to prevent or delay secondary complications, including contractures, edema, and shoulder pain, in stroke survivors with upper limb weakness. In developing this manual, we collaborated with three stroke rehabilitation occupational therapy experts from diverse backgrounds. These experts reviewed the manual and provided valuable insights, validating its effectiveness. We employed a qualitative approach by asking the experts three open-ended questions for each section, recording their responses, and analyzing the data to identify valuable themes. However, due to the small sample size, no clear themes emerged. Instead, we received suggestions, which were confirmed by an external corroborator. This manual is intended to benefit both occupational therapists and stroke survivors. Therapists can use it to anticipate and address potential complications, while survivors can learn techniques for home exercises and post-therapy care. The overarching goal is to provide stroke survivors with a simplified approach to rehabilitation and encourage active participation in their recovery, thereby improving their quality of life

Selection of Post-Acute Care for Stroke Patients

Background: Significant variation exists in post-acute care for stroke survivors. This study examines referral practices of occupational and physical therapists for patients after acute stroke. Method: Occupational therapists (OTs) and physical therapists (PTs) were surveyed either electronically or in person at a national conference. The respondents selected the most appropriate referral for each of five case vignettes. The referral choices included Inpatient Rehabilitation Facility (IRF), Skilled Nursing Facility (SNF), Long-Term Acute Care Hospital (LTACH), home with home services, or home with outpatient services. Demographic data included practice location, setting, and duration. The respondents were also asked to rate how strongly 15 clinical factors influence their referral decisions. Results: The 33 OTs and 41 PTs favored similar referrals. Consensus was observed in four of the five cases. No differences were observed among the respondents based on practice location, practice setting, or number of years in practice and the referrals. Prognosis for functional improvement and pre-stroke functional status were identified as the most important factors influencing referral decisions. Conclusion: Further studies are needed to define areas of broad consensus as well as areas of disagreement, with subsequent efforts to clarify optimal treatment algorithms for patients who currently receive variable rehabilitative care